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EVs Are Essential Grid-Scale Storage

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Re: EVs Are Essential Grid-Scale Storage

#221

Post by sgt »

mnw21cam wrote: post #200
discordance wrote: post #4

Earlier quoted context omitted.

$300/kWh for home storage is readily available. E.g. https://signaturesolar.com/eg4-ll-lithium-battery-24v-200ah/

Deep cycle lead-acid batteries are available around £100/kWh, and they'll last pretty-much as long as a LiFePo if managed sensibly.

Managing lead-acid sensibly in my experience means never letting levels go below 40%. Temperature too I suppose.

I didn't know they could last as long as LiFePo though. Is this really true?

If this is true, why don't we just use more lead-acid batteries then?

Re: EVs Are Essential Grid-Scale Storage

#222

Post by fwungy »

Yizahi wrote: post #10

Aren't people wary about using their very expensive car batteries for the grid? E.g. imagine you plug in your phone for the night, but instead of a single top up change it is now constantly discharging and charging again. Lifetime of pocket sized batteries is not too great even now, and in such scenario they will go bust 2-3 times faster, in year instead of 3 or so. Also discharge swings would be probably much bigger…

The problem is that the battery is not the only expense on the car. You have to depreciate the vehicle's value too, because there is a good chance a BEV will be disposed of rather than have a battery replacement.

Say the lifespan of a battery is 10 years. If you lose 10% of the charges for grid storage you're looking at replacement at the 9 year mark. Until we know that the vehicle itself will be reusable at that point you need to depreciate the battery usage against the cost of the entire vehicle, and be compensated for it.

Re: EVs Are Essential Grid-Scale Storage

#223

Post by moffkalast »

mnw21cam wrote: post #200
discordance wrote: post #4

Earlier quoted context omitted.

$300/kWh for home storage is readily available. E.g. https://signaturesolar.com/eg4-ll-lithium-battery-24v-200ah/

Deep cycle lead-acid batteries are available around £100/kWh, and they'll last pretty-much as long as a LiFePo if managed sensibly.

> they'll last pretty-much as long as a LiFePo if managed sensibly

[Citation needed]

Typically lead acid lifespan is around 10x less than lifepo4, even if kept within spec.

But in practice it's hard to keep them in spec too, shit sulphates immediately when you look at it wrong.

Re: EVs Are Essential Grid-Scale Storage

#224

Post by fwungy »

sokoloff wrote: post #176
iso1210 wrote: post #81

Earlier quoted context omitted.

This does work today at grid scale, people use their home batteries (either on wheels or not) to charge/discharge to the grid in the UK all the time. If someone builds that storage facility to do it commercially then great. > rooftop solar can't exist without special subsidies Yet it does

There are special subsidies for rooftop solar here in the US (Solar Investment Tax Credit). Are there not subsidies for solar where you live? https://www.seia.org/initiatives/solar-investment-tax-credit... > The solar Investment Tax Credit (ITC) is one of the most important federal policy mechanisms to support the growth of solar energy in the United States. Since the ITC was enacted in 2006, the U.S. solar industry…

Subsidies are a terrible way to run energy policy because they can change quickly with politics. Big players stay away from big commitments to subsidy based markets.

Re: EVs Are Essential Grid-Scale Storage

#225

Post by whazor »

londons_explore wrote: post #25
Yizahi wrote: post #10

Aren't people wary about using their very expensive car batteries for the grid? E.g. imagine you plug in your phone for the night, but instead of a single top up change it is now constantly discharging and charging again. Lifetime of pocket sized batteries is not too great even now, and in such scenario they will go bust 2-3 times faster, in year instead of 3 or so. Also discharge swings would be probably much bigger…

Luckily, any degradation can all be predicted ahead of time. A 60kwh car battery might cost $10k, and allow 2000 charge cycles. So each kwh cycled into and out of the battery costs 8 cents. So a smart algorithm can decide it's worth draining the battery back into the grid if the profit to be made is more than 8 cents. Buuuut ... Delaying charging till later is free. So another car owner's car might see on the futures…

Here in EU, day ahead prices that are available to me as consumer are now ranging from €0.18/kWh to €0.34/kWh in the same day (winter). So that is 16 cents per kWh diff to profit from. I guess there is some energy loss with charging and de-charging.

Since prices a per day, announced the day before, the algorithm is not that complicated.

Also, if I install solar panels, the electricity just goes back into the grid, and I would get money for it. For the car it would be the same, just reverse the electricity into the grid. So it is mostly just the connecting the day-ahead prices, plus the cars and wall chargers returning electricity of-course.

Re: EVs Are Essential Grid-Scale Storage

#226

Post by [deleted] »

jacquesm wrote: post #192
trashtester wrote: post #46

Earlier quoted context omitted.

> Buuuut... Delaying charging till later is free. This functionality is already there. > So each kwh cycled into and out of the battery costs 8 cents. This is quite much. If you add other infra overhead, feeding power back into the grid is not going to produce much revenue for the individual unless the selling price is maybe 20 cents above the price when charging. On the other hand, something that MAY make more sense…

For a blackout situation your car won't be of much help: any inverter that is grid tied will refuse to come on as long as there isn't a low impedance functioning grid connection present. Typically they'll measure the conditions for a minute or two, then make the connection (you'll hear a relay trip) and then bit by bit the inverter starts pushing power by advancing its on phase relative to the grid. If that doesn't s…

[deleted]

Re: EVs Are Essential Grid-Scale Storage

#227

Post by [deleted] »

jacquesm wrote: post #192
trashtester wrote: post #46

Earlier quoted context omitted.

> Buuuut... Delaying charging till later is free. This functionality is already there. > So each kwh cycled into and out of the battery costs 8 cents. This is quite much. If you add other infra overhead, feeding power back into the grid is not going to produce much revenue for the individual unless the selling price is maybe 20 cents above the price when charging. On the other hand, something that MAY make more sense…

For a blackout situation your car won't be of much help: any inverter that is grid tied will refuse to come on as long as there isn't a low impedance functioning grid connection present. Typically they'll measure the conditions for a minute or two, then make the connection (you'll hear a relay trip) and then bit by bit the inverter starts pushing power by advancing its on phase relative to the grid. If that doesn't s…

[deleted]

Re: EVs Are Essential Grid-Scale Storage

#228

Post by sokoloff »

fwungy wrote: post #224
sokoloff wrote: post #176

Earlier quoted context omitted.

There are special subsidies for rooftop solar here in the US (Solar Investment Tax Credit). Are there not subsidies for solar where you live? https://www.seia.org/initiatives/solar-investment-tax-credit... > The solar Investment Tax Credit (ITC) is one of the most important federal policy mechanisms to support the growth of solar energy in the United States. Since the ITC was enacted in 2006, the U.S. solar industry…

Subsidies are a terrible way to run energy policy because they can change quickly with politics. Big players stay away from big commitments to subsidy based markets.

Subsidies of “do this this year and we’ll pay you $X” work and are relied upon. Subsidies like the CF that was the SREC market are indeed highly suspect and should not be relied upon, as generators of SRECs can attest.

Re: EVs Are Essential Grid-Scale Storage

#229

Post by ajross »

danans wrote: post #217
ajross wrote: post #114

Earlier quoted context omitted.

House batteries are never purchased in isolation. They're what amounts to a luxury add-on to a much bigger solar system, so you'd expect to see a "markup". That may change with the recent rollback of net metering in CA, which is making a battery system a requirement to reach break even on cost.

> That may change with the recent rollback of net metering in CA, which is making a battery system a requirement to reach break even on cost. NEM3.0 doesn't make a battery a requirement to break even on costs, it just extends the payback time of solar without batteries by 3-5 years. It reduces the still absurdly long payback time of home battery storage somewhat, though. Only when you can sell power back to the grid…

I've seen a lot of different numbers thrown around (and to be clear: I'm in Oregon and not part of the fight). Let it suffice that NEM3.0 makes the relative benefits of a battery for time shifting (and thus the costs of a solar system without a battery, as was typical for early installations) much, much higher.

Re: EVs Are Essential Grid-Scale Storage

#230

Post by r00fus »

Yizahi wrote: post #10

Aren't people wary about using their very expensive car batteries for the grid? E.g. imagine you plug in your phone for the night, but instead of a single top up change it is now constantly discharging and charging again. Lifetime of pocket sized batteries is not too great even now, and in such scenario they will go bust 2-3 times faster, in year instead of 3 or so. Also discharge swings would be probably much bigger…

I have a 6 year old EV with very minimal degradation doing all sorts of stuff that is frowned on: charging up to 100% all the time, using fast chargers regularly, and even letting the car sit outside on hot days (it does warn me if it's >100F to get it into the garage).

So no, I'm not really worried as I don't drive a Leaf and my car has industry-standard cooling system for the battery pack.

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